Eight years after her sudden disappearance in Egypt, a severely traumatized teenager is returned to her shattered family in New Mexico, triggering a visceral nightmare as they realize she is hosting an ancient, demonic parasite.

When Polly receives a mysterious box, it comes with one rule: place inside something she needs, something she hates, and something she loves. If she doesn’t obey, it will consume everything—and everyone—she’s ever known.